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arXiv:2012.04513 · Physical review. B./Physical review. B

Correlated electrons in a crystalline topological insulator

F. Manghi

Published Mar 9, 2021• 2 citations
arXivHTMLPDF

Abstract

We study the effects of electron-electron interaction in a three-dimensional crystalline topological insulator by adding on-site repulsion to the single-particle Hamiltonian and solving the many-body problem within cluster perturbation theory. The goal is to clarify how many-body effects modify the topological phase that stems from the crystal symmetries. Tuning the strength of the on-site interaction, we show that band inversion disappears in the bulk and surface states lose their metallic character.

DOI
10.1103/physrevb.103.115114

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We study the effects of electron-electron interaction in a three-dimensional crystalline topological insulator by adding on-site repulsion to the single-particle Hamiltonian and solving the many-body problem within cluster perturbation theory. The goal is to clarify how many-body effects modify the topological phase that stems from the crystal symmetries. Tuning the strength of the on-site interaction, we show that band inversion disappears in the bulk and surface states lose their metallic character.
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The natural existence of crystalline symmetry in real materials manifests the importance of understanding crystalline symmetry-protected topological phases, especially for interacting systems. In this paper, we systematically construct and classify all the point-group crystalline topological superconductors and insulators in three-dimensional (3D) interacting fermion systems using the novel concept of a topological crystal. The corresponding higher-order topological surface theory can also be systematically studied via higher-order bulk-boundary correspondence. In particular, we discover several intrinsically interacting topological phases that cannot be realized in any free-fermion systems. Moreover, the crystalline equivalence principle for 3D interacting fermionic systems is also verified, with an additional subtle “twist” on the spin of fermions.
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